20815442 has 8 divisors (see below), whose sum is σ = 31336716. Its totient is φ = 10369872.

The previous prime is 20815441. The next prime is 20815447. The reversal of 20815442 is 24451802.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20511841 + 303601 = 4529^2 + 551^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (20815441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18233 + ... + 19340.

Almost surely, 2^20815442 is an apocalyptic number.

20815442 is a deficient number, since it is larger than the sum of its proper divisors (10521274).

20815442 is a wasteful number, since it uses less digits than its factorization.

20815442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37852.

The product of its (nonzero) digits is 2560, while the sum is 26.

The square root of 20815442 is about 4562.3943275434. The cubic root of 20815442 is about 275.0818136742.

The spelling of 20815442 in words is "twenty million, eight hundred fifteen thousand, four hundred forty-two".